Living in extreme heat may age your body like smoking, study finds
Living in extreme heat may speed up aging—similar to the effects of smoking, researchers say. Here’s what the study reveals.
AccuWeather Forecasting Senior Director Dan DePodwin and AccuWeather Climate Expert Brett Anderson discuss the top headlines related to climate change in the March 7 edition of Climate In The News.
Living in a place with a lot of extreme heat may do more than just make you uncomfortable—it could actually cause your body to age faster.
A new study from the USC Leonard Davis School of Gerontology found that older adults living in hot, humid places—like Phoenix—show signs of faster aging at the cellular level, even when other factors like smoking, drinking or income are taken into account.
In fact, researchers say the impact of long-term heat exposure is similar to the effects of smoking or heavy alcohol use.
"Just because you live in an area with more heat days, you're aging faster biologically," said lead author Eunyoung Choi. “The impact is similar to the effect of smoking and drinking.”
A billboard displays a temperature of 118 degrees Fahrenheit (48 degrees Celcius) during a heat wave in Phoenix, Arizona. (Photo credit: Getty Images)
To figure this out, scientists looked at blood samples from more than 3,600 people over the age of 56. They used a tool called an epigenetic clock to measure biological age—basically, how old your body acts, not just how many birthdays you’ve had.
They found that people living in areas with frequent high heat and humidity had more signs of aging at the molecular level. The biggest effects were seen in those exposed to heat over long periods—months or years—not just during short heat waves.
In Phoenix, where temperatures topped 90°F for 188 days last year—and hit 100°F or more on 140 of those days—the risks could be especially high.
Melissa decided to do a little dashboard cooking in 112-degree Phoenix heat: mac & cheese, quesadillas, pot pies and even a burger “grilled to perfection.”
The researchers used the heat index, not just temperature, because humidity makes it harder for the body to cool down—especially in older adults who don’t sweat as efficiently.
This study helps explain how heat affects people’s genes, not just how they feel. Over time, those small changes can add up and lead to more serious health issues.
As climate change leads to longer, hotter summers, experts say cities need to prepare—especially for aging populations. That could mean more shade, better cooling access and smarter urban planning to protect public health.
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